This invention relates to a method and apparatus for signaling a power consuming location of load conditions.
It is generally recognized that the electric power generating capacity is not, at the present time, utilized efficiently. This inefficiency results from the fact that the load on the power generating system is not distributed evenly throughout a 24-hour day. There are peak periods in which the load is extremely heavy and the full capacity of the power generating is demanded, and there are light periods in which there is an excess of power generating capacity. The result has been a power generating system which is often overloaded during peak periods of load and inefficient during light periods. This unbalanced condition has increased pressure to expand the power generating capacity to better handle the peak load periods with a resulting increase in inefficiency during the light periods.
In an effort to smooth out the peaks and valleys in power consumption, power companies encourage the reduction of optional load, e.g., residential air conditioners, during typical peak load periods. In some instances, the optional load has been removed from the system by means of a time clock.
U.S. Pat. No. 3,683,343--Feldman et al discloses a system wherein signals are superimposed on the power lines so as to indicate loads in the system thereby providing the customer with an indication of the load. The superimposed signals are also utilized to determine the scale factor of a meter so as to provide the customer with a variation in electric rates depending upon the load condition on the power system.
Despite the above-mentioned efforts to achieve certain efficiency and economy in the power generating systems, there has been no wide-scale, consistent use of such technqiues. The use of time clocks has been less than satisfactory since the load conditions at a certain time on one day may differ considerably from the load conditions at the same time on another day. Superimposing load condition signals on the power lines along with the power generating frequency has also met with little if no use. This may in part be attributable to the cost of installing the additional signaling equipment at the generating source. Such signaling equipment may also be less than desirable under circumstances where electrical noise erroneously indicates a change in load. Furthermore, superimposing a signal on the power lines might be fraudulently duplicted so as to permit the benefit of a reduced rate during a peak load period where varying metering rates are provided.